Problem Description:
The task is to write the numbers that come
before and
after the given numbers in the sequence from 1 to 20. The worksheet provides a series of numbers, and for each number, you need to fill in the boxes with the numbers immediately preceding and succeeding it.
Solution Approach:
1.
Identify the given number: For each row, the middle box contains a specific number.
2.
Determine the number before: Subtract 1 from the given number.
3.
Determine the number after: Add 1 to the given number.
4.
Ensure the result is within the range 1-20: Since the problem specifies numbers between 1 and 20, the results should not go outside this range.
Step-by-Step Solution:
#### Row 1:
- Given number:
12
- Number before: \( 12 - 1 = 11 \)
- Number after: \( 12 + 1 = 13 \)
- Result:
11, 12, 13
#### Row 2:
- Given number:
5
- Number before: \( 5 - 1 = 4 \)
- Number after: \( 5 + 1 = 6 \)
- Result:
4, 5, 6
#### Row 3:
- Given number:
19
- Number before: \( 19 - 1 = 18 \)
- Number after: \( 19 + 1 = 20 \)
- Result:
18, 19, 20
#### Row 4:
- Given number:
14
- Number before: \( 14 - 1 = 13 \)
- Number after: \( 14 + 1 = 15 \)
- Result:
13, 14, 15
#### Row 5:
- Given number:
17
- Number before: \( 17 - 1 = 16 \)
- Number after: \( 17 + 1 = 18 \)
- Result:
16, 17, 18
#### Row 6:
- Given number:
2
- Number before: \( 2 - 1 = 1 \)
- Number after: \( 2 + 1 = 3 \)
- Result:
1, 2, 3
#### Row 7:
- Given number:
10
- Number before: \( 10 - 1 = 9 \)
- Number after: \( 10 + 1 = 11 \)
- Result:
9, 10, 11
#### Row 8:
- Given number:
7
- Number before: \( 7 - 1 = 6 \)
- Number after: \( 7 + 1 = 8 \)
- Result:
6, 7, 8
#### Row 9:
- Given number:
8
- Number before: \( 8 - 1 = 7 \)
- Number after: \( 8 + 1 = 9 \)
- Result:
7, 8, 9
#### Row 10:
- Given number:
15
- Number before: \( 15 - 1 = 14 \)
- Number after: \( 15 + 1 = 16 \)
- Result:
14, 15, 16
Final Answer:
\[
\boxed{
\begin{array}{ccc}
11 & 12 & 13 \\
4 & 5 & 6 \\
18 & 19 & 20 \\
13 & 14 & 15 \\
16 & 17 & 18 \\
1 & 2 & 3 \\
9 & 10 & 11 \\
6 & 7 & 8 \\
7 & 8 & 9 \\
14 & 15 & 16 \\
\end{array}
}
\]
Parent Tip: Review the logic above to help your child master the concept of before and after numbers worksheet.
